Genetic insights into seed development, flowering and diversity in faba bean: pre-breeding for sustainable agriculture

Faba bean (Vicia faba L.) is a nutrient-rich legume with significant potential for sustainable agriculture in northern climates, yet breeding advancements remain limited. This thesis integrates phenotypic, genetic, and biochemical analyses to develop genomic tools and accelerate the improvement of key agronomic traits and seed quality. A global diversity panel of 220 faba bean accessions, evaluated across two growing seasons, revealed substantial phenotypic variation in flowering time, plant height, yield, and seed composition. Notably, no yield penalty was observed for higher protein content, challenging traditional trade-offs and suggesting potential for simultaneous improvement. A genome-wide association study (GWAS) identified 51 SNP markers linked to ten agronomic traits. Transcriptomic and biochemical analyses of seed development elucidated the temporal regulation of nutrient accumulation, revealing early protein deposition in both embryo and endosperm, followed by progressive starch accumulation and consistently low lipid content. Gene expression analyses identified key transcription factors and metabolic pathways governing seed storage. Additionally, the first comprehensive characterization of the PEBP gene family in faba bean identified 11 members, including allelic variation in VfTFL1a, a gene linked to determinacy. These findings provide novel genetic resources for marker-assisted breeding, advancing our understanding of nutrient accumulation and the genetic regulation of plant architecture. This work contributes to the development of high-performing faba bean varieties, supporting sustainable food and feed systems in northern climates.